NATO and U.S. flags flutter as U.S. Air Force F-22 Raptor fighter flies over the military air base in Siauliai, Lithuania, April 27, 2016. (Photo by Ints Kalnins/Reuters)

A member of the Revolutionary Armed Forces of Colombia (FARC) pose for a picture at a camp in the Colombian mountains on February 2005. (Photo by Frank Piasecki Poulsen)

Members of the Coney Island Polar Bear Club warm up before swimming at the beach at Coney Island in New York, December 15, 2013. (Photo by Eric Thayer/Reuters)

A U.S. soccer fan pretends that Uruguay's soccer striker Luis Suarez is biting him as he takes a selfie next to an Adidas advertisement featuring Suarez near Copacabana beach in Rio de Janeiro, Brazil, Thursday, June 26, 2014. FIFA banned Suarez from all football activities for four months on Thursday for biting an opponent at the World Cup, a punishment that rules him out of the rest of the tournament. (Photo by Matt Dunham/AP Photo)

Waura Indians wrestle during this year's “quarup”, a ritual held over several days to honour in death a person of great importance to them, in Xingu National Park, Mato Grosso State, Brazil August 25, 2013. (Photo by Ueslei Marcelino/Reuters)

A woman looks out from her stall selling traditional garments and textiles at a market in Ashgabat February 8, 2012. (Photo by Aman Mehinli/Reuters)

A group of people are seen on a Victoria line train in London, England during the first night of the Night Tube service on August 19 2016. The Central line and Victoria line are the first to operate a Night service with further lines expected to be running by the end of the year. (Photo by SWNS.com)

Wang uses a mobile phone as she take a rest in her room at the accommodation where patients and their family members stay while seeking medical treatments in Beijing, China, June 23, 2016. Wang, who suffers from cervical cancer, came from Inner Mongolia to seek treatment at a specialist hospital in Beijing. (Photo by Kim Kyung-Hoon/Reuters)